# Author:Zhang Yu
import pika
import uuid

class MathRpcClient(object):
    def __init__(self):
        self.connection = pika.BlockingConnection(pika.ConnectionParameters("127.0.0.1"))
        self.channel = self.connection.channel()
        result = self.channel.queue_declare(queue="rpc")
        self.callback_queue = result.method.queue

        self.channel.basic_consume(on_message_callback=self.on_response,auto_ack=True,queue=self.callback_queue)

    def on_response(self,ch,method,props,body):
        if self.corr_id == props.correlation_id:
            self.response = body

    def call(self,n):
        self.response =None
        self.corr_id = str(uuid.uuid4())
        self.channel.basic_publish(exchange='',
                                   routing_key="rpc_queue",
                                   properties=pika.BasicProperties(reply_to=self.callback_queue,
                                                                   correlation_id=self.corr_id,
                                                                   ),
                                   body=str(n))
        while self.response is None:
            self.connection.process_data_events()
        return int(self.response)

math_rpc = MathRpcClient()
print("[*] Requesting fib(50)")
response = math_rpc.call(50)
print("[.] Got",response)